Optical switches are useful for a variety of applications, including fiber optic communications. In one design approach, optomechanical components are used to direct light from a desired optical input to a desired optical output. Conventional optomechanical switches include switches employing moving prisms and switches employing moving fibers, among others.
If insertion losses are to be maintained within an acceptable range, the various components of an optical switch ordinarily need to be precisely aligned relative to each other. Precise alignment requirements can significantly increase manufacturing costs, reduce manufacturing yields, and constrain the temperature ranges and vibration intensities to which the switches can be subjected.
In U.S. Pat. No. 5,999,669, Pan et al. describe an optical switch in which switching is effected by introducing a prism between collimating lenses to redirect the optical signal to an alternative lens. The prism has a cross-section defining a parallelogram, so that the optical signal is deflected twice within the prism. Pan et al. describe a 1×2 switch configuration using a single prism, and a 1×4 switch configuration using three independently movable prisms. The described 1×4 configuration may require correlating the alignment of multiple prisms during the switch assembly.